Oh really Schmickers.. is there a way to know the difference between Rotavirus and general (if it is general) gastro? My DS had it really bad a few months back. Was vomitting for a few days, diarrohea for over a week, was very dehydrated (skin was very scaley), lathargic, fever, etc.
Well, rotavirus is just a type of gastro, along with the many other viruses and bacteria that cause gastro. Rotavirus has a specific smell, but that would be pretty hard to describe... Any gastro, if it gets a little one dehydrated, is dangerous.

WRT people getting rotavirus multiple times, if the child in question has some sort of immunosuppression that is preventing them mounting an adequate response to the rotavirus infection, then that might account for the repeated infections with the virus - if the child in question has a PEG tube and seizures, then I am guessing they have some sort of serious medical condition that might contribute to their susceptibility to the virus and their inability to properly seroconvert.

Having said that, it is possible that they will simply fail to mount an adequate response to the vaccine, as well - immunity occurs by the same mechanism, either with the vaccine or the germ itself. For that reason, I think that they may not be happy to offer the rotavirus immunisation late or in multiple doses, but that would be up to you to discuss with your paediatrician.

And finally, one of the things to remember with rota in babies under 6 months of age is that, in the absence of being able to move around by themselves, to get rotavirus they must be exposed to the germ somehow. Basic hand hygeine is the best defence against rotavirus, especially in babies.